The present invention relates to programmed timing control and more particularly wherein the programmability of the time of occurrence of the pulse is generated by a combination of reference masks or patterns with a generated pattern.
In microprocessor controlled apparatus, requirements arise for the timing of events. As microprocessor capability continually increases, the number of apparatus and the number of events controlled by a microprocessor greatly increase. Since many apparatus and processors have critical times for the initiation of diverse functions, requirements for generating timing pulses in an inexpensive and flexible manner has greatly increased. The generation of such timing pulses should reach a minimal system cost by an astute collection of hardware and computer programming. A timing pulse generation method for enabling such selections is needed in the microprocessor area.
Timing devices are known which measure a plurality of elapsed times; that is, a continuously running clock supplies timing signals to a plurality of memory devices which store the elapsed time on the occurrence of any of a plurality of events. The respective memory is then latched to the time stored in memory. In this manner, the time of event is accurately recorded. This apparatus, however, does not provide for the selective generation of timing pulses, it only measures what has occurred. It also does not provide for successive timed actuations via highly flexible programmable relationships.
Computerized timers, of course, are known. External counters are known to be program loaded by a computer. In such apparatus, a clock drives the program loaded counter to zero which then interrupts the computer. This, however, required one counter for each timing pulse. As the number of timing pulses required continually increases, this arrangement becomes unduly expensive or on the other hand, to utilize that in a program, requires a lot of attention to the elapsed time of program execution. As programs are changed, such elapsed times can also change. Therefore, the maintenance and improvement of programs in such a situation becomes unduly burdensome.
Multiple timing in computerized systems includes measuring elapsed times of subroutines. This again, as in the first illustration, only measures actual elapsed time. It does not provide for flexible generation of timing pulses independent of other events.